V8Binding.h   [plain text]

/*
* Copyright (C) 2009 Google Inc. All rights reserved.
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#ifndef V8Binding_h
#define V8Binding_h

#include "AtomicString.h"
#include "BindingElement.h"
#include "BindingSecurity.h"
#include "MathExtras.h"
#include "PlatformString.h"
#include "V8DOMWrapper.h"

#include <v8.h>

namespace WebCore {
    
    class EventListener;
    class EventTarget;
    class V8BindingDOMWindow;

    // Instantiate binding template classes for V8.
    class V8Binding {
    public:
        typedef v8::Handle<v8::Value> Value;
        typedef V8BindingDOMWindow DOMWindow;
    };
    typedef BindingSecurity<V8Binding> V8BindingSecurity;
    typedef BindingElement<V8Binding> V8BindingElement;
    
    enum ExternalMode {
        Externalize,
        DoNotExternalize
    };
    
    template <typename StringType>
    StringType v8StringToWebCoreString(v8::Handle<v8::String> v8String, ExternalMode external);

    // Convert v8 types to a WebCore::String. If the V8 string is not already
    // an external string then it is transformed into an external string at this
    // point to avoid repeated conversions.
    inline String v8StringToWebCoreString(v8::Handle<v8::String> v8String)
    {
        return v8StringToWebCoreString<String>(v8String, Externalize);
    }
    String v8NonStringValueToWebCoreString(v8::Handle<v8::Value>);
    String v8ValueToWebCoreString(v8::Handle<v8::Value> value);

    // Convert v8 types to a WebCore::AtomicString.
    inline AtomicString v8StringToAtomicWebCoreString(v8::Handle<v8::String> v8String)
    {
        return v8StringToWebCoreString<AtomicString>(v8String, Externalize);
    }
    AtomicString v8NonStringValueToAtomicWebCoreString(v8::Handle<v8::Value>);
    AtomicString v8ValueToAtomicWebCoreString(v8::Handle<v8::Value> value);

    // Return a V8 external string that shares the underlying buffer with the given
    // WebCore string. The reference counting mechanism is used to keep the
    // underlying buffer alive while the string is still live in the V8 engine.
    v8::Local<v8::String> v8ExternalString(const String&);

    // Convert a string to a V8 string.
    inline v8::Handle<v8::String> v8String(const String& string)
    {
        return v8ExternalString(string);
    }

    // Enables caching v8 wrappers created for WebCore::StringImpl.  Currently this cache requires
    // all the calls (both to convert WebCore::String to v8::String and to GC the handle)
    // to be performed on the main thread.
    void enableStringImplCache();

    // Convert a value to a 32-bit integer.  The conversion fails if the
    // value cannot be converted to an integer or converts to nan or to an infinity.
    int toInt32(v8::Handle<v8::Value> value, bool& ok);

    // Convert a value to a 32-bit integer assuming the conversion cannot fail.
    inline int toInt32(v8::Handle<v8::Value> value)
    {
        bool ok;
        return toInt32(value, ok);
    }

    // Convert a value to a 32-bit unsigned integer.  The conversion fails if the
    // value cannot be converted to an unsigned integer or converts to nan or to an infinity.
    uint32_t toUInt32(v8::Handle<v8::Value> value, bool& ok);

    // Convert a value to a 32-bit unsigned integer assuming the conversion cannot fail.
    inline uint32_t toUInt32(v8::Handle<v8::Value> value)
    {
        bool ok;
        return toUInt32(value, ok);
    }

    inline float toFloat(v8::Local<v8::Value> value)
    {
        return static_cast<float>(value->NumberValue());
    }

    inline long long toInt64(v8::Local<v8::Value> value)
    {
        return static_cast<long long>(value->IntegerValue());
    }

    // FIXME: Drop this in favor of the type specific v8ValueToWebCoreString when we rework the code generation.
    inline String toWebCoreString(v8::Handle<v8::Value> object)
    {
        return v8ValueToWebCoreString(object);
    }
    
    String toWebCoreString(const v8::Arguments&, int index);

    // The string returned by this function is still owned by the argument
    // and will be deallocated when the argument is deallocated.
    inline const uint16_t* fromWebCoreString(const String& str)
    {
        return reinterpret_cast<const uint16_t*>(str.characters());
    }

    bool isUndefinedOrNull(v8::Handle<v8::Value> value);

    v8::Handle<v8::Boolean> v8Boolean(bool value);

    String toWebCoreStringWithNullCheck(v8::Handle<v8::Value> value);

    AtomicString toAtomicWebCoreStringWithNullCheck(v8::Handle<v8::Value> value);

    String toWebCoreStringWithNullOrUndefinedCheck(v8::Handle<v8::Value> value);
 
    v8::Handle<v8::String> v8UndetectableString(const String& str);

    v8::Handle<v8::Value> v8StringOrNull(const String& str);

    v8::Handle<v8::Value> v8StringOrUndefined(const String& str);

    v8::Handle<v8::Value> v8StringOrFalse(const String& str);

    double toWebCoreDate(v8::Handle<v8::Value> object);

    v8::Handle<v8::Value> v8DateOrNull(double value);
    
    v8::Persistent<v8::FunctionTemplate> createRawTemplate();

    struct BatchedAttribute;
    struct BatchedCallback;
    
    v8::Local<v8::Signature> configureTemplate(v8::Persistent<v8::FunctionTemplate>,
                                               const char* interfaceName,
                                               v8::Persistent<v8::FunctionTemplate> parentClass,
                                               int fieldCount,
                                               const BatchedAttribute*, 
                                               size_t attributeCount,
                                               const BatchedCallback*,
                                               size_t callbackCount);
    
    v8::Handle<v8::Value> getElementStringAttr(const v8::AccessorInfo&,
                                               const QualifiedName&);
    void setElementStringAttr(const v8::AccessorInfo&,
                              const QualifiedName&,
                              v8::Local<v8::Value>);

    
    v8::Persistent<v8::String> getToStringName();
    v8::Persistent<v8::FunctionTemplate> getToStringTemplate();
    
    // V8Parameter is an adapter class that converts V8 values to Strings
    // or AtomicStrings as appropriate, using multiple typecast operators.
    enum V8ParameterMode {
        DefaultMode,
        WithNullCheck,
        WithUndefinedOrNullCheck
    };
    template <V8ParameterMode MODE = DefaultMode>
    class V8Parameter {
    public:
        V8Parameter (v8::Local<v8::Value> object) :m_v8Object(object) { }
        operator String();
        operator AtomicString();
    private:
        v8::Local<v8::Value> m_v8Object;
    };
    
    template<> inline V8Parameter<DefaultMode>::operator String() { return toWebCoreString(m_v8Object); }
    template<> inline V8Parameter<WithNullCheck>::operator String() { return toWebCoreStringWithNullCheck(m_v8Object); }
    template<> inline V8Parameter<WithUndefinedOrNullCheck>::operator String() { return toWebCoreStringWithNullOrUndefinedCheck(m_v8Object); }

    template<> inline V8Parameter<DefaultMode>::operator AtomicString() { return v8ValueToAtomicWebCoreString(m_v8Object); }
    template<> inline V8Parameter<WithNullCheck>::operator AtomicString() { return toAtomicWebCoreStringWithNullCheck(m_v8Object); }
    template<> inline V8Parameter<WithUndefinedOrNullCheck>::operator AtomicString() { return toAtomicWebCoreStringWithNullCheck(m_v8Object); }

} // namespace WebCore

#endif // V8Binding_h